Binocular Rivalry

1. Equipment

1. To easily produce binocular rivalry, use a pair of red-cyan glasses (Figure 1).
   
   Figure 1. A pair of red-cyan rivalry glasses. The glasses make it possible to present two overlaid images such that only one arrives to each eye. The red lens will filter out all but red light before it reaches a viewer’s eye, and the cyan lens will filter out all but blue light. This means that a blue tinted image won’t make it to the eye with the red lens, and a red tinted image won’t make it to the eye behind the blue lens
2. A stopwatch will also be necessary.

2. Stimulus

1. An easy demonstration having to do with rivalry involves nonsense words superimposed on something meaningful.
2. In PowerPoint©, create a slide with the word ‘Hello’ written in blue, and on top of it write the letters ‘Cfbal’ written in red. Make the word on top 50% transparent. It will look like this (Figure 2).

Figure 2. Sample stimulus for a demonstration of binocular rivalry. The word ‘Hello’ is written in blue, and in a 50% transparent red, the nonsense letters ‘Cfbal’ are written on top.

3. Running the Experiment

1. Print the slide on a piece of white paper. Seat a participant in front of the paper and ask them to put on the glasses.
2. Set the stopwatch to countdown 120 seconds.
3. Instruct the participant that every ten seconds they will be asked to report what they see, and that they should answer in one of three ways, ‘Hello,’ ‘Cfbal,’ or ‘Mixed / Unclear’.
4. Begin the count, and every ten seconds, ask the participant what they see. Mark down the responses.